ABSTRACT
The issue optical clearing technique is promising for the enhancement of many optical diagnostic and therapeutical methods. Despite the wide development of different optical clearing approaches, it is difficult to achieve effective skin optical clearing in vivo. The main problems are the physiological response of living tissue to the action of the optical clearing agents and enhancers, the need to use biocompatible agents, and the need to overcome the natural skin barrier. Therefore, most investigations have been carried out for in vitro or ex vivo models and have been not realized for humans in vivo. Besides, many approaches have been developed effectively for animals only.
This chapter focuses on the features and possibilities of in vivo skin optical clearing in humans using biocompatible chemical and physical enhancers of epidermal permeability, and the application of these approaches to some optical diagnostic methods, such as optical coherence tomography (OCT), reflectance and transmittance spectroscopy, fluorescence spectroscopy, Raman spectroscopy and microscopy, laser speckle contrast imaging, hyperspectral imaging, and photoacoustic imaging. The authors also briefly review the structure and optical properties of human skin.
